Discovery II
AUTOMATIC GEARBOX - ZF4HP22 - 24
DESCRIPTION AND OPERATION
44-19
Fault effects and warning indications
Fault code,
OBD II
(TestBook)
Fault description
Effect
Warning lamp
illumination
MIL
Sport/
Manual
P0705
(14, 23)
* Gear position switch,
incorrect outputs
Maintains current gear in low range, limp
home mode in high range. Shift pressure to
maximum, harsh gear shifts/engagement.
On On
P0721
(21)
* Downshift safety
monitor prevented
downshift which would
have caused engine
overspeed
Maintains current gear in low range, limp
home mode in high range. Shift pressure to
maximum, harsh gear shifts/engagement.
On
On
P0722
(22)
* Torque converter
slipping
Maintains current gear in low range, limp
home mode in high range. Shift pressure to
maximum, harsh gear shifts/engagement.
On
On
P0731
(29)
* Ratio monitoring,
implausible 1st gear
ratio
No apparent effect
On
On
P0732
(30)
* Ratio monitoring,
implausible 2nd gear
ratio
No apparent effect
On
Off
P0733
(31)
* Ratio monitoring,
implausible 3rd gear
ratio
No apparent effect
On
Off
P0734
(32)
* Ratio monitoring,
implausible 4th gear
ratio
No apparent effect
On
Off
P0741
(5)
* Torque converter
lock-up clutch fault
May affect driveability.
On
Off
P0743
(7, 25)
* Torque converter
lock-up solenoid (MV
3), open or short circuit
Limp home mode in low and high ranges. Shift
pressure to maximum, harsh gear shifts/
engagement.
On
On
P0748
(10, 28)
* Pressure regulating
solenoid (MV 4), open
or short circuit
Limp home mode in low and high ranges. Shift
pressure to maximum, harsh gear shifts/
engagement.
On
On
P0753
(8, 26)
* Shift solenoid (MV 1),
open or short circuit
Limp home mode in low and high ranges. Shift
pressure to maximum, harsh gear shifts/
engagement.
On
On
P0758
(9, 27)
* Shift solenoid (MV 2),
open or short circuit
Limp home mode in low and high ranges. Shift
pressure to maximum, harsh gear shifts/
engagement.
On
On
P1562
(24)
* Battery supply below
9V while engine
running
Maintains current gear in low range, limp
home mode in range. Shift pressure to
maximum, harsh gear shifts/engagement.
Off
On
P1601
(4)
* ECU, EEPROM
checksum
Limp home mode in low and high ranges. Shift
pressure to maximum, harsh gear shifts/
engagement.
On
On
P1606
(3)
* EEPROM
No apparent effect
On†
Off
P1606
(6)
* Watchdog
No apparent effect
On
On
P1612
(2)
* Solenoid valves
power supply relay,
sticking closed or open
circuit
Limp home mode in low and high ranges. Shift
pressure to maximum, harsh gear shifts/
engagement.
On
On